title: Activation of an innate immune response in the schistosome-transmitting snail Biomphalaria glabrata by specific bacterial PAMPs.
abstract: Injection of crude lipopolysaccharide (LPS) from Escherichia coli into the hemocoel of Biomphalaria glabrata stimulates cell proliferation in the amebocyte-producing organ (APO). However, it is not known if mitogenic activity resides in the lipid A or O-polysaccharide component of LPS. Moreover, the possible role of substances that commonly contaminate crude LPS and that are known to stimulate innate immune responses in mammals, e.g., peptidoglycan (PGN), protein, or bacterial DNA, is unclear. Therefore, we tested the effects of the following injected substances on the snail APO: crude LPS, ultrapurified LPS (lacking lipoprotein contamination), two forms of lipid A, (diphosphoryl lipid A and Kdo2-lipid A), O-polysaccharide, Gram negative PGN, both crude and ultrapurified (with and without endotoxin activity, respectively), Gram positive PGN, PGN components Tri-DAP and muramyl dipeptide, and bacterial DNA. Whereas crude LPS, ultrapurified LPS, and crude PGN were mitogenic, ultrapurified PGN was not. Moreover, LPS components, PGN components, and bacterial DNA were inactive. These results suggest that it is the intact LPS molecule which stimulates cell division in the APO.
authors.affiliation: Department of Biology, University of San Francisco, San Francisco, CA 94117, USA. Electronic address: sullivan@usfca.edu.
authors.forename: John T
authors.initials: JT
authors.lastname: Sullivan
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Belloir
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000276:immunology; D000818:Animals; D001700:Biomphalaria / Q000276:immunology* / Q000469:parasitology; D049109:Cell Proliferation / Q000187:drug effects; D004269:DNA, Bacterial / Q000276:immunology; D003960:Diaminopimelic Acid / Q000031:analogs & derivatives / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology; D007113:Immunity, Innate; D008050:Lipid A / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D009842:Oligopeptides / Q000276:immunology; D010457:Peptidoglycan / Q000276:immunology; D012547:Schistosoma / Q000276:immunology
chemical_list: D004269:DNA, Bacterial; C555437:L-Ala-gamma-D-Glu-meso-diaminopimelic acid; D008050:Lipid A; D008070:Lipopolysaccharides; D009842:Oligopeptides; D010457:Peptidoglycan; D000119:Acetylmuramyl-Alanyl-Isoglutamine; D003960:Diaminopimelic Acid
keywords: 1/3 dilution of phosphate buffered saline; APO; Amebocyte-producing organ; DMSO; EU; Kdo; LPS; LPS from Escherichia coli O111:B4; LPS from Escherichia coli O127:B8; LPS-B4; LPS-B4, ultrapurified; LPS-B4U; LPS-B8; MDP; Mitotic cell division; Molluscs; NAG; PAMP; PBS; PGN; PGN from Bacillus subtilis; PGN from E. coli K12, ultrapurified; PGN from E. coli O111-B4; PGN-BS; PGN-EC; PGN-ECU; PRR; Peptidoglycan; Schistosoma; TLR; Toll-like receptor; Tri-DAP; amebocyte-producing organ; dimethyl sulfoxide; endotoxin unit; keto-3-deoxyoctonoic acid; l-alanine-γ-d-glutamate-meso-diaminopimelate; lipopolysaccharide; muramyl dipeptide; n-acetylglucoseamine; pathogen associated molecular pattern; pattern recognition receptor; peptidoglycan